A method of joining together at the laying side concrete products including construction materials such as box culverts, side channels and U-shaped channels must conventionally meet the requirements, (a) providing a rigid connectivity ensuring a structural integration of the concrete products; (b) providing a flexibility at the joining points of the concrete products in order to ensure earthquake resistant properties; and (c) providing water cutoff properties for preventing any leakage of liquid.
However, there have hitherto existed no joining methods that satisfy all the requirements (a) to (c) mentioned above.
Joining methods that merely provide the rigid connectivity of (a) above include the method as shown in FIG. 12, in which opposed joining faces 1, 1 of concrete products A, B are adhered to each other with an adhesive S of cement mortar, synthetic resin or the like.
Another joining method is illustrated in FIG. 13, in which joining faces 1, 1 of concrete products A, B are provided with respective, opposed projecting steel plates 50, 50, which are welded together to join the concrete products.
A third joining method is illustrated in FIG. 14, in which an appropriate number of steel rods 51 are provided between joining faces 1, 1 of concrete products A, B and at one end linked to one concrete product A and at the other end linked to the other concrete product B to join them together.
Further, a fourth joining method is illustrated in FIG. 15, in which steel rods 52, 52, a sleeve 53 and a filler 54 are used to connect the concrete products A, B together.
The conventional adhesive-using method as shown in FIG. 12, however, entails a deficiency that the joining points, when the concrete products A, B are joined together, are subject to stresses and thus to fracture.
The conventional method as shown in FIG. 13, in which the opposed steel plates 50, 50 projecting at the joining faces 1, 1 of the concrete products A, B are welded, entails a deficiency that it requires skill and lots of time and labor for the welding operation, resulting in an inefficient joining operation as well as an increase in construction costs. In addition, the steel plates 50, 50 are susceptible to corrosion.
The conventional method as shown in FIG. 14 which uses steel rods 51 to join the concrete products A, B entails a deficiency that it involves the selection of the number of steel rods 51 to use and the positions where to provide the steel rods 51 as well as the thickness of the steel rods 51 to use from the point of view of design in consideration of the required strength and structure, resulting in a complicated designing. Likewise, with the conventional method as shown in FIG. 15, the selection of steel rods 52 and their assembly to the sleeve 53 and design have been complicated. In addition, both the joining methods have required lots of time and labor, leading to inefficiency in joining the concrete products A, B and an increase in construction costs, material costs and production costs.
Further, an O-ring, a rubber packing or the like has been used to prevent leakage of water between the concrete products A, B joined.
The present invention has been conceived in order to overcome the above deficiencies, and an object of the present invention is to provide a joining method and a joining structure as well as a form for concrete products, which enable an unskilled person to join concrete products together with a simple handling operation, which impart a structural firmness and a sufficient rigid connectivity as well as excellent earthquake resistant properties and water cutoff properties, and which are easy to produce and design and capable of reducing construction costs and material costs.